Lighting systems can include a plurality of lights connected to a transformer. There may be one or more “legs” or sets of wires coming out of the transformer, each connected to at least one lighting module. A timer box connects to the transformer. The user programs the on/off times and all of the lights energize in unison, such that all lighting modules connected to a particular transformer turn ON or OFF together regardless of which leg they are on.
Some manufacturers can provide lighting systems with addressable lighting modules. The timer box of the traditional lighting system is replaced with a lighting controller that supplies the lighting modules with a separate power and data signal. Each lighting module has an address and is independently addressable by the lighting controller via the data signal. These networked lighting systems provide the lighting modules with two sets of wires instead of the one or more legs. One set provides a power signal to illuminate the lights, lamps, or LEDs and a second set provides the lighting module with a data signal. The user programs the lighting controller to turn-on and turn-off lights of a lighting module at individual addresses such that a single lighting module can turn-on or turn-off independently of the other lighting modules in the network, when, for example, the data signal carries the address of a particular lighting module.